What is Ataxia?
Ataxia is a rare neurological disease. It is progressive – affecting a person’s ability to walk, talk, and use fine motor skills.
Ataxia is a degenerative disease of the nervous system. Many symptoms of Ataxia can mimic those of being drunk – slurred speech, stumbling, falling, and incoordination. All are related to degeneration of the part of the brain, called the cerebellum, that is responsible for coordinating movement. Ataxia is a disease that affects people of all ages. Age of symptom-onset can vary widely, from childhood to late-adulthood. Complications from the disease are serious, oftentimes debilitating, and can be life-shortening. Ataxia is an umbrella term used to classify a group of diseases that include:
Multiple System Atrophy
Symptoms vary by person and type of Ataxia. Symptom onset and progression vary as well. Symptoms may worsen slowly, over decades – or quickly, over mere months. Common symptoms of Ataxia are lack of coordination, slurred speech, trouble eating and swallowing, eye movement abnormalities, deterioration of fine motor skills, difficulty walking, gait abnormalities, tremors, and heart problems. Individuals with Ataxia often require the use of wheelchairs, walkers, and/or scooters to aid in their mobility.
Treating Ataxia requires an individualized approach. A person will work closely with their neurologist to develop a plan to address the symptoms of Ataxia. Speech and language therapy, occupational therapy, and physical therapy are common treatment options. They are sometimes used in conjunction with medication therapy to help manage symptoms. There is no treatment or cure for Ataxia yet.
Ataxia is diagnosed using a combination of strategies that may include medical history, family history, and a complete neurological evaluation. Various blood tests may be performed to rule out other possible disorders which may present similar symptoms. Genetic blood tests are now available for some types of hereditary Ataxia.
Hereditary Ataxias are genetic, which means they are caused by a defect in a certain gene that is present from the start of a person’s life. Hereditary Ataxias can be divided into those that are dominantly inherited and those that are recessively inherited.
Ataxia results in abnormal proteins that affect nerve cells, primarily in the cerebellum and the spinal cord. Eventually the affected nerve cells begin to function poorly and ultimately degenerate. As the disease progresses, muscles become less and less responsive to commands from the brain, causing coordination problems to become more pronounced.
Autosomal Dominant Ataxia Gene
Each child of a parent with an autosomal dominant Ataxia gene has a 50% chance of inheriting the Ataxia gene. Since the gene is dominant, if a gene is passed on to the child from one parent, the child will develop the disease. Men and women are affected equally.
Autosomal Recessive Ataxia Gene
Autosomal recessive inherited diseases also affect males and females equally, but both parents must be carriers of the Ataxia gene and each must pass on the Ataxia gene to the child for the child to develop the disease. Each child of parents who are carriers of a recessive gene have a 25% chance of developing the disease, a 50% chance of inheriting just one of the Ataxia genes, becoming a carrier themselves, and a 25% chance of inheriting no Ataxia genes. Because a single recessive Ataxia gene does not cause symptoms, it can be passed on in a family for generations without being recognized. Therefore, there can appear to be no “family history” of Ataxia if the disease was inherited as a recessive gene.
Ataxia Gene Identification
The first Ataxia gene was identified in 1993 for a dominantly inherited type. It was called “Spinocerebellar Ataxia Type1 (SCA1)”. Subsequently, as additional dominant genes were found they were called SCA2, SCA3, etc. Generally, the number behind the SCA refers to the order in which the gene was found. At this time, 36 different gene mutations have been found. We have dominant Ataxia classifications from SCA1 to SCA36. Genes have also been located for some of the recessive Ataxias; the most common being Friedreich’s Ataxia (FRDA). Ataxia with Oculomotor Apraxia Type 1 and Type 2 (AOA1 and AOA2) have also been identified.
What is Sporadic Ataxia?
There is a large group of people who have symptoms of Ataxia that usually begin in adulthood and who have no known family history of the disease. This is called Sporadic Ataxia and can be difficult to diagnose. There are many acquired and hereditary causes of Ataxia which must be ruled out before a diagnosis of Sporadic Ataxia can be made. Sporadic Ataxia can be either “pure cerebellar” if only the cerebellum is affected or cerebellar plus, if the Ataxia is accompanied by additional symptoms such a neuropathy, dementia, or weakness, rigidity, or spasticity of the muscles. Disability may be greater and progress more quickly with the cerebellar plus form of Sporadic Ataxia. The cerebellar plus form of sporadic ataxia is also known as Sporadic Olivopontocerebellar Ataxia (Sporadic OPCA) or multiple system atrophy, cerebellar type (MSA-C).
Ataxia as a Symptom
The word “ataxia” can also be used to describe a symptom of incoordination which can be associated with infections, injuries, other diseases, or degenerative changes in the central nervous system. This form of ataxia is different from the neurological disease. For people who have ataxia as a symptom of another medical condition such as head injury, stroke, MS, alcoholism, etc., we recommend that you contact the organization related to your specific condition for the most up-to-date and accurate information.